The hypothalamic-pituitary-adrenal (HPA)-axis is a central component of the body's neuroendocrine response to stress. Its major end-product cortisol has profound effects on mood and behavior. Although it has often been suggested, it remains unknown whether differences in HPA-axis physiology are part of an individual's vulnerability to psychopathology, and constitute a causal factor in its development. In order to study the contribution of HPA-axis physiology to the development of psychopathology, we measured HPA-axis physiology in a community-cohort of 1768 10-12 year-old children. The aims of the here presented study were twofold: (1) to obtain data on HPA-axis function in a large cohort of pre- and early-adolescent children, both in terms of total hormonal output and in terms of the dynamics of cortisol secretion (by means of the cortisol awakening response); and (2) to study potential confounders of the cortisol-psychopathology relationship in this age group, such as season of sampling, age, gender, pubertal development, perinatal variables and BMI. We found a wide interindividual variability in HPA-axis function. An increase in cortisol in the first 30 min after awakening was present in 70.7% of children, but the increase appears lower in children than in adults. In addition, this study suggests that season of sampling and gender may act as potential confounders in the cortisol-psychopathology relationship. We will follow these children longitudinally for the development of psychopathology in the period from childhood into adulthood. This period covers adolescence, which is a critical time for the appearance and development of psychiatric disorders.

Awakening response, Children, Cortisol, Gender, Puberty, Seasonal effects,
Pediatric Psychiatry

Rosmalen, J.G.M, Oldehinkel, A.J, Ormel, J, de Winter, A.F, Buitelaar, J.K, & Verhulst, F.C. (2005). Determinants of salivary cortisol levels in 10-12 year old children; A population-based study of individual differences. Psychoneuroendocrinology, 30(5), 483–495. doi:10.1016/j.psyneuen.2004.12.007